#include<bits/stdc++.h>
using namespace std;
 
const int maxn = 1e5 + 10;
int a[maxn], b[maxn];
int n, k;
vector<int> g[maxn];
 
int lsh(int x) {
  int L = 1, R = n;
  while(L <= R) {
    int mid = (L + R) / 2;
    if(b[mid] > x) R = mid - 1;
    else if(b[mid] < x) L = mid + 1;
    else return mid;
  }
  return 0;
}
 
int main() {
  scanf("%d%d", &n, &k);
  for(int i = 1; i <= n; i ++) {
    scanf("%d", &a[i]);
    b[i] = a[i];
  }
  sort(b + 1, b + 1 + n);
  for(int i = 1; i <= n; i ++) {
    a[i] = lsh(a[i]);
  }
  for(int i = 1; i <= n; i ++) {
    g[a[i]].push_back(i);
  }
  int ans = 1;
  for(int i = 1; i <= n; i ++) {
    if(g[i].size() <= 1) continue;
    for(int j = 1; j < g[i].size(); j ++) {
      int L = 0, R = j, p = j;
      while(L <= R) {
        int mid = (L + R) / 2;
        if((g[i][j] - g[i][mid] + 1) - (j - mid + 1) <= k) {
          p = mid;
          R = mid - 1;
        } else {
          L = mid + 1;
        }
      }
      ans = max(ans, j - p + 1);
    }
  }
  printf("%d\n", ans);
   
   
  return 0;
}